Machine vision sensors, typically designed for controlled environments, have proven highly beneficial in traffic systems like automatic license plate recognition (ALPR). Their superior image quality and reliability across extended temperature ranges make them ideal for such applications. However, these sensors face challenges in outdoor conditions—especially under extreme lighting scenarios like direct sunlight. Fortunately, experienced camera designers can implement specific functionalities to mitigate these limitations.

The Challenge: Obsolescence and the Need for Improvement

In 2010, Adimec partnered with a leading manufacturer of intelligent traffic systems to address an urgent issue: their existing cameras were becoming obsolete. Traffic systems rely heavily on image quality for accurate optical character recognition (OCR), so the stakes were high. The client evaluated multiple options and ultimately chose Adimec based on superior image quality, alongside GigE Vision compatibility and cost-effectiveness.

The outdoor lighting conditions in traffic environments are dynamic and unpredictable, posing significant challenges to camera performance. While CCD sensors traditionally offered better image quality for OCR, their inherent limitations—specifically smear and blooming artifacts—became problematic under direct sunlight. These issues could lead to inaccurate readings in ALPR systems. To solve this, Adimec implemented a smear compensation function, effectively minimizing the impact of these artifacts. This improvement dramatically enhanced system accuracy during daylight operations.

For nighttime performance, an external IR LED was integrated and synchronized with the camera’s trigger output, ensuring clear license plate recognition even in low-light conditions.

The Result: Increased Accuracy and Cost Savings

Adimec’s solution not only boosted system reliability but also contributed to cost reduction. By leveraging Camera Link technology for high-speed video transmission and real-time triggering, Adimec delivered exceptional performance. However, the need for frame grabbers and cable length limitations made this interface relatively expensive. To address these constraints, some image enhancement algorithms were embedded directly into the camera, enabling compatibility with the GigE Vision standard.

This approach eliminated the need for costly frame grabbers and allowed for longer cable runs while reducing overall system costs. Adimec’s client successfully secured a major traffic project tender by adopting this tailored solution.

The Solution: Integrating Advanced Algorithms

The original ALPR system relied on Camera Link, which provided excellent bandwidth for high-quality video transmission—a necessity for precise OCR. Its real-time triggering capabilities further enhanced its suitability for traffic applications. However, the associated costs and hardware requirements (like frame grabbers) were significant drawbacks.

By embedding image enhancement algorithms into the camera itself, Adimec transitioned to GigE Vision technology while maintaining performance standards. This shift reduced expenses by simplifying system components and utilizing more affordable cables with extended reach capabilities.

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Last Updated: 2025-09-04 19:31:24